The overall objective of this research is to study the physiological aspects of amino acid fermentations by clostridia. Studies are being conducted to determine ATP yields from the fermentation of various amino acid pairs by Clostridium sporogenes, and to assess the effect of different amino acids on the adenylate energy charge of cells. Experiments are underway to determine the role of a unique proline dehydrogenase in C. sporogenes, and to elucidate the pathways by which glutamic acid, proline, ornithine and arginine are interconverted.